1. Technical Field
The present invention relates to capacitor fabrication and, more particularly, to forming finned capacitors as part of a fin field effect transistor fabrication process.
2. Description of the Related Art
Decoupling capacitors are used to shield circuit elements from noise generated by other circuit elements. Noise is directed through the capacitor, reducing the effect it has elsewhere. For example, changing power demands for a device may manifest as changing current demand. When the current demand for a device changes, the power supply does not respond instantly and, as a result, voltage at the device changes until the power supply can adapt. When events take place that have a frequency higher than what can be accommodated by a voltage regulator, noise occurs. The decoupling capacitor works as backup energy storage. If voltage drops, the capacitor can quickly provide the shortfall for a short period of time within a given frequency range.
When using decoupling capacitors on integrated circuits (ICs), it is advantageous to place capacitors close to the devices they serve. However, previous circuit designs for decoupling capacitors substantially increase the number of steps used in the fabrication process and do not benefit from the steps used to create nearby fin field effect transistors.